api-mock-server

Name: api-mock-server
Author: girijashankarj

27stars3forks

How to install api-mock-server?

girijashankarj/cursor-handbook/api-mock-server

$npx -y skills add girijashankarj/cursor-handbook --skill api-mock-server

Installs into the current project.

Summary

Generate a mock API server from OpenAPI specs, TypeScript interfaces, or endpoint descriptions for frontend development and testing. Use when the user asks to create a mock server, fake API, or stub endpoints.

Files · 1

View on GitHub

SKILL.md

1	# Skill: API Mock Server
2
3	Generate a lightweight mock API server that returns realistic responses for frontend development and integration testing.
4
5	## Trigger
6	When the user asks to mock an API, create a fake backend, stub endpoints, or generate a dev server from a spec.
7
8	## Prerequisites
9	- [ ] API endpoints to mock identified
10	- [ ] Response shapes known (from OpenAPI spec, TypeScript types, or examples)
11
12	## Steps
13
14	### Step 1: Choose Approach
15
16	\| Approach \| Tool \| Best For \|
17	\|----------\|------\|----------\|
18	\| JSON Server \| `json-server` \| Quick REST mock from a JSON file \|
19	\| MSW (Mock Service Worker) \| `msw` \| Browser/Node request interception for tests \|
20	\| Express mock \| `express` \| Custom logic, delays, error simulation \|
21	\| Prism \| `@stoplight/prism-cli` \| Auto-mock from OpenAPI spec \|
22
23	### Step 2: Generate Mock Data
24	- [ ] Use the `test-data-factory` skill to create realistic data
25	- [ ] Generate 10–50 records per resource
26	- [ ] Include relationships (foreign keys reference valid IDs)
27
28	### Step 3a: JSON Server (Simplest)
29
30	```json
31	// mock-db.json
32	{
33	"users": [
34	{ "id": "usr_001", "name": "Alice Johnson", "email": "alice@example.com", "role": "admin" },
35	{ "id": "usr_002", "name": "Bob Smith", "email": "bob@example.com", "role": "user" }
36	],
37	"orders": [
38	{ "id": "ord_001", "userId": "usr_001", "status": "CONFIRMED", "total": 99.99 }
39	]
40	}
41	```
42
43	```bash
44	npx json-server mock-db.json --port 3001 --delay 200
45	```
46
47	### Step 3b: MSW Handlers (for Tests)
48
49	```typescript
50	// mocks/handlers.ts
51	import { http, HttpResponse } from 'msw';
52
53	export const handlers = [
54	http.get('/api/v1/users', () => {
55	return HttpResponse.json({
56	data: [
57	{ id: 'usr_001', name: 'Alice Johnson', email: 'alice@example.com' },
58	],
59	meta: { correlationId: 'mock-123', timestamp: new Date().toISOString() },
60	});
61	}),
62
63	http.post('/api/v1/users', async ({ request }) => {
64	const body = await request.json();
65	return HttpResponse.json(
66	{ data: { id: 'usr_new', ...body }, meta: { correlationId: 'mock-456' } },
67	{ status: 201 }
68	);
69	}),
70
71	http.get('/api/v1/users/:id', ({ params }) => {
72	if (params.id === 'not-found') {
73	return HttpResponse.json(
74	{ error: { code: 'NOT_FOUND', message: 'User not found' } },
75	{ status: 404 }
76	);
77	}
78	return HttpResponse.json({
79	data: { id: params.id, name: 'Alice Johnson' },
80	});
81	}),
82	];
83	```
84
85	```typescript
86	// mocks/server.ts (Node.js)
87	import { setupServer } from 'msw/node';
88	import { handlers } from './handlers';
89	export const server = setupServer(...handlers);
90
91	// mocks/browser.ts (Browser)
92	import { setupWorker } from 'msw/browser';
93	import { handlers } from './handlers';
94	export const worker = setupWorker(...handlers);
95	```
96
97	### Step 3c: Express Mock (Custom Logic)
98
99	```typescript
100	// mock-server.ts
101	import express from 'express';
102
103	const app = express();
104	app.use(express.json());
105
106	// Simulate latency
107	app.use((req, res, next) => {
108	setTimeout(next, 100 + Math.random() * 200);
109	});
110
111	app.get('/api/v1/resources', (req, res) => {
112	const page = parseInt(req.query.cursor as string) \|\| 0;
113	res.json({
114	data: generateResources(20),
115	meta: {
116	cursor: page + 20,
117	hasMore: page < 100,
118	correlationId: req.headers['x-correlation-id'] \|\| 'mock',
119	},
120	});
121	});
122
123	// Error simulation
124	app.get('/api/v1/error', (req, res) => {
125	res.status(500).json({ error: { code: 'INTERNAL_ERROR', message: 'Simulated error' } });
126	});
127
128	app.listen(3001, () => console.log('Mock server on http://localhost:3001'));
129	```
130
131	### Step 4: Add Error Scenarios
132	- [ ] 400 — validation error (missing required field)
133	- [ ] 401 — unauthorized (expired/missing token)
134	- [ ] 404 — resource not found
135	- [ ] 429 — rate limited
136	- [ ] 500 — internal server error
137	- [ ] Timeout simulation (delayed response)
138
139	### Step 5: Add to package.json Scripts
140	```json
141	{
142	"scripts": {
143	"mock": "npx json-server mock-db.json --port 3001",
144	"mock:msw": "ts-node mocks/server.ts"
145	}
146	}
147	```
148
149	### Step 6: Document
150	- [ ] List all mocked endpoints
151	- [ ] Document special behaviors (error triggers, delays)
152	- [ ] Note any differences from real API
153
154	## Rules
155	- NEVER include real credentials or PII in mock data
156	- ALWAYS match the real API's response envelope format
157	- ALWAYS include realistic latency simulation (100–300ms)
158	- ALWAYS include error scenarios alongside happy paths
159	- Mock data should use `@example.com` emails, fake names, and UUID-style IDs
160	- Response shapes must match the real API contract exactly
161
162	## Completion
163	Working mock server with realistic data, error scenarios, and run instructions.
164
165	## If a Step Fails
166	- No API spec: Build from TypeScript interfaces or example responses
167	- **Complex aut

People who liked this also viewed

6 picks

Type

api-mock-server

27stars3forks

View on GitHub

How to install api-mock-server?

girijashankarj/cursor-handbook/api-mock-server

$npx -y skills add girijashankarj/cursor-handbook --skill api-mock-server

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# Skill: API Mock Server
2
3	Generate a lightweight mock API server that returns realistic responses for frontend development and integration testing.
4
5	## Trigger
6	When the user asks to mock an API, create a fake backend, stub endpoints, or generate a dev server from a spec.
7
8	## Prerequisites
9	- [ ] API endpoints to mock identified
10	- [ ] Response shapes known (from OpenAPI spec, TypeScript types, or examples)
11
12	## Steps
13
14	### Step 1: Choose Approach
15
16	\| Approach \| Tool \| Best For \|
17	\|----------\|------\|----------\|
18	\| JSON Server \| `json-server` \| Quick REST mock from a JSON file \|
19	\| MSW (Mock Service Worker) \| `msw` \| Browser/Node request interception for tests \|
20	\| Express mock \| `express` \| Custom logic, delays, error simulation \|
21	\| Prism \| `@stoplight/prism-cli` \| Auto-mock from OpenAPI spec \|
22
23	### Step 2: Generate Mock Data
24	- [ ] Use the `test-data-factory` skill to create realistic data
25	- [ ] Generate 10–50 records per resource
26	- [ ] Include relationships (foreign keys reference valid IDs)
27
28	### Step 3a: JSON Server (Simplest)
29
30	```json
31	// mock-db.json
32	{
33	"users": [
34	{ "id": "usr_001", "name": "Alice Johnson", "email": "alice@example.com", "role": "admin" },
35	{ "id": "usr_002", "name": "Bob Smith", "email": "bob@example.com", "role": "user" }
36	],
37	"orders": [
38	{ "id": "ord_001", "userId": "usr_001", "status": "CONFIRMED", "total": 99.99 }
39	]
40	}
41	```
42
43	```bash
44	npx json-server mock-db.json --port 3001 --delay 200
45	```
46
47	### Step 3b: MSW Handlers (for Tests)
48
49	```typescript
50	// mocks/handlers.ts
51	import { http, HttpResponse } from 'msw';
52
53	export const handlers = [
54	http.get('/api/v1/users', () => {
55	return HttpResponse.json({
56	data: [
57	{ id: 'usr_001', name: 'Alice Johnson', email: 'alice@example.com' },
58	],
59	meta: { correlationId: 'mock-123', timestamp: new Date().toISOString() },
60	});
61	}),
62
63	http.post('/api/v1/users', async ({ request }) => {
64	const body = await request.json();
65	return HttpResponse.json(
66	{ data: { id: 'usr_new', ...body }, meta: { correlationId: 'mock-456' } },
67	{ status: 201 }
68	);
69	}),
70
71	http.get('/api/v1/users/:id', ({ params }) => {
72	if (params.id === 'not-found') {
73	return HttpResponse.json(
74	{ error: { code: 'NOT_FOUND', message: 'User not found' } },
75	{ status: 404 }
76	);
77	}
78	return HttpResponse.json({
79	data: { id: params.id, name: 'Alice Johnson' },
80	});
81	}),
82	];
83	```
84
85	```typescript
86	// mocks/server.ts (Node.js)
87	import { setupServer } from 'msw/node';
88	import { handlers } from './handlers';
89	export const server = setupServer(...handlers);
90
91	// mocks/browser.ts (Browser)
92	import { setupWorker } from 'msw/browser';
93	import { handlers } from './handlers';
94	export const worker = setupWorker(...handlers);
95	```
96
97	### Step 3c: Express Mock (Custom Logic)
98
99	```typescript
100	// mock-server.ts
101	import express from 'express';
102
103	const app = express();
104	app.use(express.json());
105
106	// Simulate latency
107	app.use((req, res, next) => {
108	setTimeout(next, 100 + Math.random() * 200);
109	});
110
111	app.get('/api/v1/resources', (req, res) => {
112	const page = parseInt(req.query.cursor as string) \|\| 0;
113	res.json({
114	data: generateResources(20),
115	meta: {
116	cursor: page + 20,
117	hasMore: page < 100,
118	correlationId: req.headers['x-correlation-id'] \|\| 'mock',
119	},
120	});
121	});
122
123	// Error simulation
124	app.get('/api/v1/error', (req, res) => {
125	res.status(500).json({ error: { code: 'INTERNAL_ERROR', message: 'Simulated error' } });
126	});
127
128	app.listen(3001, () => console.log('Mock server on http://localhost:3001'));
129	```
130
131	### Step 4: Add Error Scenarios
132	- [ ] 400 — validation error (missing required field)
133	- [ ] 401 — unauthorized (expired/missing token)
134	- [ ] 404 — resource not found
135	- [ ] 429 — rate limited
136	- [ ] 500 — internal server error
137	- [ ] Timeout simulation (delayed response)
138
139	### Step 5: Add to package.json Scripts
140	```json
141	{
142	"scripts": {
143	"mock": "npx json-server mock-db.json --port 3001",
144	"mock:msw": "ts-node mocks/server.ts"
145	}
146	}
147	```
148
149	### Step 6: Document
150	- [ ] List all mocked endpoints
151	- [ ] Document special behaviors (error triggers, delays)
152	- [ ] Note any differences from real API
153
154	## Rules
155	- NEVER include real credentials or PII in mock data
156	- ALWAYS match the real API's response envelope format
157	- ALWAYS include realistic latency simulation (100–300ms)
158	- ALWAYS include error scenarios alongside happy paths
159	- Mock data should use `@example.com` emails, fake names, and UUID-style IDs
160	- Response shapes must match the real API contract exactly
161
162	## Completion
163	Working mock server with realistic data, error scenarios, and run instructions.
164
165	## If a Step Fails
166	- No API spec: Build from TypeScript interfaces or example responses
167	- **Complex aut

People who liked this also viewed

6 picks

Type